Streamline Theme – Questions on "featured image"

These forums are for general discussion on WordPress, CSS and design and site feedback. Official support for StudioPress themes is offered exclusively through the My StudioPress member area. Responses in this forum are not guaranteed. Please note that this forum will require a new username, separate from the one used for My.StudioPress.

I was wondering whether the "featured image", that originally comes with the theme and is placed above posts, can be customized to show on specific posts rather than on ALL posts or NO posts.

Currently I have disabled it due to it giving me trouble with my old posts; giving rise to duplicate pictures and adding to that that my old blog posts pictures are in terrible resolution and do not look good in the format of the featured image.(There is an option to disable the duplicate pictures in the theme options, but I have crossed that box and it is still giving me issues on a few posts)

Now I think the "featured image" of Streamline looks great, but only when done correctly. It looks awful on my old posts. What I would like to do is to disable it for all old posts, but add it to my new posts and select images that look nice in that format.

So, is this possible to do; can I adjust for the "featured image" function above the posts to be customized per post?

I've been trying to get it working, but I'm having some trouble. I've only been toying with CSS & PHP files for two weeks and barely understand how to structure it.

Question:

1.Do I need to collect every PageID and insert manually into the code? (Because none of my old posts fit the format for the featured above picture and would therefore not look well with it)

2. Once having collected these PageIDs (not the hard part), WHERE and HOW do I put them into the PHP, could you post an example? When I say how, what I'm really asking is how to separate the IDs and how to "finish" the code.
Would it be like this?

The issue has now been resolved, though it took some time to manually look up and write all the IDs.

I want to note for future readers that in my case it had to be is single not is page, because all of my old blog posts that look horrible with the Streamline featured image function were single posts.

Thanks a lot Brad,
I will likely post a few more questions in the coming days and weeks seeing as how I have so much to learn and so much to do until I am content with the appearance of my blog. I hope they too will be answered as quickly and skillfully!

I've been trying to use the CSS code (and checked out your post on it on your blog) and yeah it works, but it effectively eliminates ALL the featured images in the posts shown on my home page/ blog template.

And I do not want to completely eliminate it, I only want it to be hidden from the "ugly", old images, that I have in my previous blog posts. I want to keep the featured pictures showing in the home page/blog template for all the new posts I make.

Thus far I have been able to eliminate the featured images inside the posts by using the ".single (array( post id)" command that you showed me.

But those ugly featured images are still showing on the home page/blog template.

Is there no way to customize it on the home page/blog template in the exact same manner that I've been able to do with the posts?

I basically just replaced where you had category to what had worked in the code above for me seeing as how there are many posts that need to be adjusted and the issue is non-category specific,. But it didn't work. I am messing up the code because I don't really understand how to write it properly yet.